Genetic diversity and population structure of Melissa officinalis L. from Iran as reveled by retrotransposon insertional polymorphism

Lemon balm (Melissa officinalis) is one of the most important medicinal herbs with diverse medical and industrial applications. In the present study, genetic diversity and relationships of 12 Iranian and two exotic populations of Melissa officinalis L. were analyzed using inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) markers. Both markers’ systems revealed a high level of polymorphism and the average percent polymorphism for IRAP and REMAP was 96.35% and 90.78%, respectively. The IRAP with mean polymorphic information content (PIC) of 0.27 and marker index (MI) of 14.4 was more polymorphic compared with REMAP (PIC = 0.28, MI = 11.7). Distance- and model-based cluster analyses and principal coordinate analysis results showed that the populations from Germany and Japan were closely clustered. The individuals from Iranian populations in most cases were also grouped together based on their origins. Our study revealed a high level of insertional polymorphism in lemon balm populations based on primers designed using barley’s retrotransposons families.